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FPDoc Onlineexperiment

TotalVariance function

In unit Math

Return total variance of values.

Declaration

pascal
function TotalVariance(const data: Array of Single): Float

Description

TotalVariance returns the total variance of the values in the data array. It returns zero if there is only one value.

The second form of the function accepts a pointer to an array of N values.

Errors

None.

See also

Example: ex49

pascal
Program Example49;

{ Program to demonstrate the TotalVariance function. }
{ @ should return typed pointer }
{$T+}

Uses math;

Type
  TExArray = Array[1..100] of Float;

Var
  I : Integer;
  ExArray : TExArray;
  TV : float;

begin
  Randomize;
  for I:=1 to 100 do
    ExArray[i]:=(Random-Random)*100;
  TV:=TotalVariance(ExArray);
  Writeln('Total variance     : ',TV:8:4);
  TV:=TotalVariance(@ExArray[1],100);
  Writeln('Total Variance (b) : ',TV:8:4);
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.